As our post-industrial rivers steadily recover from the ravages of the Industrial Revolution, it’s almost impossibly thrilling to imagine salmon returning to catchments where they used to run in thousands – all the more so, when their populations seem to be on a knife-edge in so many much more rural rivers too.

So, when this little film clip from the Mersey Rivers Trust popped up on the Urbantrout Twitter feed yesterday morning, we just sat here watching it in a kind of happy trance…